Method of and appabattts fob sizing papeb



' H. M. WHEELWRIGHT.

METHOD OF AND APPARATUS FOR SIZING PAPER.

APPLICATION FILED JULY 22,1915.

Patented Aug. 22, 1916.

17/72 Weelwa 4y dorn HENRY M. WHEELWBIGHT, OF WARE, MASSACHUSETTS.

mi'rnon or AND arraaarns ron'srz'me PAPER.

speciflcatidn of Letters Patent. Patented Aug. 22, 1916.

Application filed July 22, 1915.' Serial No. 41,375.

To all whom it may concern Be it known'that I, HENRY M. WHEEL- WRIGHT,a citizen of the United States, residin at Ware, in the county of Hampshire and tate of Massachusetts, have invented a new and useful Method of and Apparatus for Sizing Paper, of which the following is a specification;

The principal objects of this invention are to provide an improved method of treatment during the manufacture of paper, whereby one wetting, and consequently one drying, of the web will be eliminated, thus reducing the cost of manufacture, the size of theplant, and the time required, as well as doing away with the well-known difficulties encountered when a previously dried web is subjected to moisture on the paper machine and consequently swells.

Reference is to be had to the accompanying drawin in whichmatic in form of a well-known typeof paper making plant arranged for carrying out this method, and Fig. 2 is an enlarged view of the apparatus constituting a part of this invention.

Heretofore, paper has been made for example, on a Fourdrinier' machine, then subjected to the wet pressing process, drying and calendering and thereafter sized by im mersion in a size in a suitable tub. This, of course, wets the paper and necessitates a further drying. If the paper is to be subj ected to the size after it has been completely dried, immersion is the most convenient and inexpensive way of doing it. The stock canthis I subject the web to all the wet pressing operations to which it is usually subjected, and apply the size during the last wet pressing operation. I find that this is a practical and efficient way of sizing the paper, that when the sizes above mentioned are employed in this manner and at this stage of the paper making process the size will not stick to the drying drums and not become in ured in any way by the drying operation, and it will be obvious that this does away with the rewetting of the web after it is dried and entirely eliminates the subsequent redrym'g operation usually necessitated in making sized paper. f

Referring particularly to the-drawing, I have .shown the invention as applied in that type ofpaper making in which the pulp passes through a Fourdrinier machine A of any desiredtype. It passes as usual from the couch rolls a to the first wet press B, from there to the second press C, and in ordinary practice by this time about fifty per cent. of the moisture has been squeezed out of thestock but it is still a comparatively weak paper because it has not been subjected to any. drying or calendering operations.

I have shown herein the third wet press D V to which the'paper is next directed and this Figure 1 1s a side view partially diagramis illustrated more in detail than the others because it is the only element of this ap paratus which is changed by this process. In this press'there is a bottom press roll 10 and a top press roll 11. The bottom press roll dips directly, preferably, into a starch bath12 and there is a starch bath 13 adjacent to the top press roll having a sort of fountain roll 14 dipping into it and engaging the surface of the top press roll 11. I preferably use a scraping blade 15 on each of the press rolls toinsurethe delivery of a uniform film of size to the surface of the web as it passes between them. It is to be understood that these press rolls accomplish two objects. They act as smoothing rol'ls for the web in addition to applying the size to the surface thereof. It is to be understood that the web of paper does not have to be supported on a felt while passing through the press D, which, although called a wet press does not extract any appreciable amount of moisture. It is then led to the drying drums E (only a part of which are illustrated herein). It will be understood that with theexception of the extraction of moisture by the wet presses, the entire drying operation is performed after the application of the size.

I have'found that the character of the size used is an important factor in the success of this method. The size should be of one of the so-called soluble, or converted hydrolyzed starches or starch compounds, preferably feculose, which 'is a partial acetate of starch, but the thin boiling starches in general can be used. I prefer to use starch products which yield a gelatin-like 'film when a ten per cent. to twenty per cent.

solution is allowed to dry-on a glass plate and this is a characteristic of the partial starch acetates commercially known as feculose. This size should be used hot so that it will penetrate the surface of the web to a suflicient degree.

The invention is suitable for use for making paper for off-set printing, for example,

when size alone is used; also writing papers can be made to great advantage and many other kinds of surface-sized papers. It will be understood of course that colors, loading materials, etc., can be added to the starch for the usual purposes to permit of theuse of the method throughout a wider field.

Although I have illustrated and described only a single type of paper-making machine, it will be understood that the invention is applicable to other paper processes and cylinder paper machines and furthermore, that changes in the construction of the sizing press can be made by any person skilled in the art and that the exact number of wet presses can be varied without departing from the scope of this invention as expressed in the claims. Therefore, I do not wish to be limited in these respects, but

What I do claim is 1. The method of sizing paper, which consists in leading th paper from a wet press,

applyingsizing to the surface of the paper while in the air, and thereafter drying and calendering the web.

2. The method of sizing paper, which consists in forming the web on a Fourdrinier machine, leading it through a series of wet presses, applying a size of soluble starch or starch compounds to the surface of the web in the last wet press, and thereafter subjecting it to the entire drying operation.

3. The method of sizing paper, which consists in forming the web, wet pressing it to extract part of the moisture, treating both surfaces simultaneously to a size of converted hydrolyzed starch or starch compounds coming from different sources before it is otherwise dried, and thereafter drying the web.

4. The method of sizing paper, which consists in applying to the previously formed web of paper after a portion of the moisture has been extracted in a wet press, feculose size by means of a press roll to the bottom of the web, and also applying feculose size by means of a press/roll to the top of the web, and then drying.

5. The method of siz ng paper, which consists in leading the paper through a series of wet presses, while the paper is in the last wet press applying starch size to the bottom and top press rolls of said press, and thus coating the two surfaces of the web with the size, and then leading the web to the first drier cylinder.

6. A wet press for a paper making machine comprising a pair of press rolls, and

means for coating each of said rolls independently with'size so as to apply the size to the Web as it passes between them and as it is being pressed by them.

7 In an apparatus for the manufacture of paper, the combination with a paper-making machine, of a series of wet presses, the last wet press comprising a pair of press rolls, means for coating each of said rolls independently with size so as to apply the size to the web as it passes between them,

- said last wet press being in position to receive the web directly from the other wet presses, and a drier having its first drying cylinder in position to receive the web from said last wet press.

In testimony whereof I have hereunto set my hand, in the presence of two subscribing witnesses.

HENRY M. WHEELWRIGHT.

Witnesses:

LILLIAN G. TREEN, JULIA F. SHERMAN. 

